https://nicholssportbikes.com/product/nmi-flywheel-nut-2piece-set/ These are supposed to cure the problem of a loose flywheel nut. Steve
Can’t be certain but it would appear to be self-styled Ducati guru Larry “Shazaam” Kelly, who has previous with Chris Kelley and CCW. IMHO, he’s talking rubbish here and from his clutch article, he clearly has no understanding of how the quiet clutch mod works either, so sadly, he’s gone right down in my estimation.
Yeh, thought as much and already been told his name lets hope we can get back on track and the op find what the issue is!
Tough crowd. The difference in recommended tension between OEM (Gates) belts and ExactFit: All 4V engines: Gates 110 ± 5Hz, ExactFit 99 Hz 1000 2V/3V engines: Gates 140 ± 5Hz, ExactFit 99 Hz!
What are you trying to say Larry? Why is your first post on this UK Ducati Forum attacking CCW? Now let the thread run for it's intended purpose and not for whatever ill intent you are trying to peddle... Sonic Belt Tension - Ducati update The following service bulletin has been issued by Ducati North America. Note that the specs are now the same for all models 2V and 4V. There are a few omissions from the list - 748 and ST4s, but I would think that's just an oversight. All previous and new model Ducati’s requiring belt tensioning now will be standardized to the below specifications. IMPORTANT: When checking and adjusting timing belt tension at the recommended scheduled maintenance intervals, if tension reading is less than 70 Hz (minimum allowed value on all Ducati motorcycles), reset belt tension as follows: Refer to the appropriate shop manuals for cam timing procedure and belt tension setup, then reset to the below tensions for service. Model Belt tension spec for new belts upon replacement Belt tension adjustment settings for used belts when inspected value is determined to be 70 Hz or less All models: Streetfighter, 1198, 1098, 1098R 999, 998, 996, 916, 848, 749, M1100, MS4, MS4R, MS4RS, ST4, SC, ST3, ST2, SS1000 HYM 1100, MTS 1100,MTS 1000, MS2R 1000, M696, MS2R 800, M620, M400, M695, SS800, MTS 620 New Belts: 110 Hz +/- 5, Horizontal and Vertical * Used Belts: 90-100 Hz +/- 5, Horizontal and Vertical * * Please note, these values may be inaccurate on previous Ducati Technical Data posters and service manuals. Data listed above should be considered the new standard and supersedes all previous bulletins and documentation. Please print and post this bulletin to be displayed with the most current Ducati service poster. Sincerely, Ducati North America Service Department
You misunderstood my intent. I simply wanted to point out that ExactFit belts have a construction that is DIFFERENT than the OEM belts. I'm not suggesting that the quality is inferior, only that the ExactFit belts should not be tensioned to OEM/Gates specs. The service bulletin by Ducati North America stating that the specs are the same for all models 2V and 4V is out of date. Ducati Tension Levels from Gates The tension requirement with picture below was published by Gates in early 2011, about a year after the Bulletin from Ducati North America. It differs from the earlier DNA Bulletin that said that both Ducati 2-valve and 4-valve belts should be tensioned to 105-115 Hz. The reason to make this distinction is that the 2-valve motors belt tension is measured for a shorter span between pulleys, that according to physics 101, will vibrate at a higher 140 Hz frequency. This will give a tension in the belt that is the same as the 4v motors when set to 110 Hz.
I posted to show Ducati have been all over the place with their tensions - you post on one of my customers threads stating you recommend only using OEM Gates belts whilst not even understanding Ducati now source from up to 3 Far East Factories too so they are simply not available for some models. CCW have a fantastic reputation when compared to OEM belts (both are competent products for our bikes) but you are welcome to your recommendation, many would recommend otherwise... if you were not being malicious as you state then why not try to be helpful instead of changing the thread into something quite opposite... Welcome to the forum anyhoo
So Gates are no longer the sole supplier of Ducati branded belts or do Gates themselves now manufacture in or source from the Far East??
Ok finally found something out about the noise hopefully. When I pulled off the clutch assy, behind the clutch driven gear there is a spacer between the gear and the bearing in the crankcase, only thing is I found 2 x spacers insated of the 1. So where did this come from, after studying the parts list the only other spacer similar in size is between the 2 bearings within the driven clutch gear, after pulling out the bearings It was not there! So a previous mechanic has installed the clutch assy incorrectly! The purpose of this middle spacer is to provide a thrust point on the inner races of the 2 bearings when torquing up the shaft nut, with this missing the smaller bearing was stressed with the inner race being pressed out of line towards the larger bearing. Now my problem is which spacer belongs where as they are 2 different thicknesses. I am pretty sure the thicker of the 2 goes on the shaft behind the cluth driven gear because it is an exact fit on that part of the shaft, the thinner one is a rattling fit in this position. Any help much appreciated with this positioning question. Pic 1. 2 spacers found here, thicker 1 to the inside and close fit Pic2. Bearings and snapring removed from the driven clutch gear, no spacer Pic3. Bearings, snapring and the extra spacer from the shaft Pic1 Pic4. Original parts list extract
After more checking, realized that the thin ring, is the same thickness as the snap ring, makes sense now as both the outer races against the snap ring, and inner races against the spacer gives even loading all over when torqued up
Well found and I hope it's the cause of your problem but what puzzles me is the fact it was running perfectly well and the noise developed 150 miles into a run out, if it was put together wrong I would have thought the noise would have been there from the start. Hope you've got it sorted though. Steve
Yes I cannot understand it either apart from the bearing was loaded and lasted a good while before failing, that's the only explanation I have.
While I was doing all of the above, I decided to renew the 8 camshaft bearings, seeing as I had already removed so much stuff from the engine, still waiting for the off belt side ones to come, but I changed the belt side ones. To-day, I was cleaning a few things up while waiting for the rest of the bearings to arrive. When spinning the old bearings a few times, 3 of them seemed ok, but 1 of them was suspect. I flushed the oil out of all 4 bearings with electroclean and gave them a few spins, low and behold, 1 of them is really bad, I mean rough as hell, 1 is much better almost good, and 2 are good, lesson learned, hard to tell if bad when bearing is lubricated. I also did this with the 2 clutch bearings I mentioned above, same result of course This is what my bad bearing sounds like http://motograffics.co.uk/Badbearing.mp3
As the original noise from my engine was constant (apart from the rev range), with the clutch in, clutch out, and riding, I am now pretty much convinced that no noise, (well perhaps a little with the clutch in?) was coming from the above mentioned clutch bearings without the spacer, especially since I have now found a really bad cam bearing. When giving more thought to the clutch bearings thrust effect, I came to realise that, with the clutch out, everything including the shaft is turning as one unit, so bearings are not rotating within themselves, there will be no clutch bearing noise. With the clutch in, and especially with a gear engaged, the gearbox shaft is stationary but the clutch gear and basket are spinning on the shaft and perhaps producing a little noise based on the missing spacer as mentioned above. So hopefully, I am getting there now, whats left to do, change the remaining 4 cam bearings, change the 2 clutch bearings (with a new snapring and spacer as recommended by Ducati), change the o-ring behind the clutch drum, as well as the spacer o-ring, then the shaft nut serated lock washer, and box everything up again. Watch this space........
Well a long drawn out wait on off belt side cam bearings, EB seller cancelled my order after 10 days as he could not supply them! Bought again direct from a bearing company, so all cam bearings now installed. In the meantime, clutch side reassembled with new driven gear bearings, spacer and snapring.
im sorry for jumping on this post late, but after listening to the sound clips you posted it sounds like excessive side load to a bearing, rather then bearing degradation in general. this is 100% the same sound that a bearing makes when you have to 'bodge' and fan belt with a smaller one to finish a journey etc in cases like this, i would always go with the thought process 'what has changed' and that being your replacement of the belts, and the associated adjustment. without going though your post in detail, (as im at work.. ) did the idler and adjustment pulley bearings sound ok? and more importantly were the Belts the correct ones for your engine model?
